Psychology 1000 Study Guide - Comprehensive Midterm Guide: Testis Determining Factor, Prenatal Development, Object Permanence

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Dr.Mike

Document Summary

Longitudinal design: repeatedly tests the same cohort as it grows older. Sequential design: that combines the cross-sectional and longitudinal approaches. By week eight the heart of the 2-centimetre-long embryo is beating, the brain is forming, facial feature, such as eyes, can be recognized. About week 24 weeks the eyes open, by 28 weeks the fetus attains the age of viability, meaning that it is likely to survive outside the womb in case of premature birth. Female"s egg and a male"s sperm cells each have only 23 chromosomes. At conception, an egg and sperm unite to form the zygote which now contains the full set of 23 pairs found in other human cells. The y chromosome contains a specific gene, known as the tdf (testis determining factor) gene, that triggers male sexual development. Once formed, the testes secrete sex hormones called androgens that continue to direct a male pattern of organ development. Teratogens: environmental agents that cause abnormal prenatal development.